Android 13 is planning to adopt Huawei’s EROFS super file system as the default file system for read-only partitions. Mishaal Rahman has been very reliable when it comes to revealing new features in the Android system.
The EROFS super file system is a file system introduced by Huawei designed to provide better performance and storage/compression for read-only files than other read-only Linux file systems. Huawei uses the EROFS super file system in its smartphones. With the support of the patented compression algorithm, Huawei’s actual measurement can improve the random read performance of the system partition by an average of 20%, and reduce the system space occupation by 14%.
According to Mishaal Rahman, Google plans to enforce the use of EROFS on all read-only partitions of Android 13 boot devices. Google has publicly stated its intentions since around December, so it’s possible to see this move coming.
Back in December, a Google engineer repeated what a colleague told him about Android’s upcoming filesystem requirements when implementing the new system_dlkm partition, which holds dynamically loadable kernel modules for the system partition. According to him, the file system of the system_dlkm partition should be EROFS instead of EXT4.
Last month’s AOSP patch added support for building GSIs with EROFS, stating that ” EROFS is planned to replace… EXT4 as the filesystem format for read-only partitions .”
More obvious evidence is that PackageManager in the latest Android 13 beta includes two new feature announcements:
These feature declarations have not yet appeared in AOSP, but the Pixel 6 Pro’s kernel was compiled with EROFS support, which is not yet using EROFS as the partition format.
The Linux kernel 5.4 has officially merged the Huawei EROFS super file system into the mainline, and some new devices of OPPO and Xiaomi have also used EROFS.